advance piston adjustment question
#1
advance piston adjustment question
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i have two ip's and the cam that pushes the arm for the advance pistons are in different spots. one pump is off a 6.9 and you have to move the throttle a good bit before it even makes contact with the advance piston, and the other one is off a 7.3 and it doesnt have any slack at all in the adjustment. as soon as you move the throttle its pushing in on the advance piston and i think that its even pushing in on it even at idle position. how is it supposed to be adjusted (with slack or no slack)?
i have two ip's and the cam that pushes the arm for the advance pistons are in different spots. one pump is off a 6.9 and you have to move the throttle a good bit before it even makes contact with the advance piston, and the other one is off a 7.3 and it doesnt have any slack at all in the adjustment. as soon as you move the throttle its pushing in on the advance piston and i think that its even pushing in on it even at idle position. how is it supposed to be adjusted (with slack or no slack)?
#2
#3
oh no im not putting the pump in, im just trying to figure out why theres such a big difference in the adjustment between the two. also i was under the empression that the engine had to be at a higher rpm before the arm even started to push in on the advance piston. the reason im trying to figure this out is i put this engine on my timing meter to see where the timing was and adjust it accordingly, but the ip is all the way bottomed out to the passenger side and the meter is still saying it has to go some more. im trying to see if maybe the previous owner had messed with it and this is my whole problem.
#4
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Messed up timing won't cause a run away.
As to your question, I'm a little curious about that myself. I do know that the 7.3 had the injectors pulled up slightly in the prechamber, so that could account for some of the timing difference between the two engines. But I can't really say for sure if this is the only reason.
As to your question, I'm a little curious about that myself. I do know that the 7.3 had the injectors pulled up slightly in the prechamber, so that could account for some of the timing difference between the two engines. But I can't really say for sure if this is the only reason.
#5
#6
#7
Step 72 of assembly says"Put throttle shaft in idle position, squeeze throttle shaft and face cam tightly toward each other (using .005-in/.127mm feeler gauge) and rotate face cam so lower roller rests approximately in middle of low idle step, tighten screw to 30 lb-in". Hope this helps.
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#8
ok i have another question. i have a snap-on mt1480 digital timing meter, using the #1 cylender and set at a 20* offset i can hold the throttle at 2000rpm and have the meter read -0.5 and move the ip and i can get it to read just 0.5 (no negative). which reading am i looking for at 2000rpm (-0.5 or 0.5)? i have it set at -1.5 as of now and that is a 1/4 of an inch to the passenger side of the scribe marks. the truck has alot more power than it did but the fuel mileage is unbearable. i can put it back the way it was but the truck has no power but the fuel mileage is better. im kind of looking for power and fuel mileage if thats possible, but i know beggers cant be choosers.
#9
ok i have another question. i have a snap-on mt1480 digital timing meter, using the #1 cylender and set at a 20* offset i can hold the throttle at 2000rpm and have the meter read -0.5 and move the ip and i can get it to read just 0.5 (no negative). which reading am i looking for at 2000rpm (-0.5 or 0.5)? i have it set at -1.5 as of now and that is a 1/4 of an inch to the passenger side of the scribe marks. the truck has alot more power than it did but the fuel mileage is unbearable. i can put it back the way it was but the truck has no power but the fuel mileage is better. im kind of looking for power and fuel mileage if thats possible, but i know beggers cant be choosers.
#10
I would love to answer your question, but I am not at all familiar with Snap On timing meter.
My guess would be that -1.5 is 1.5 degrees before TDC.
And .05 would be .05 ATDC.
I am running about 10 BTDC, but mine is not exactly stock.
Yes, I have black smoke
Yes, I have power
Yes, it sucks down the fuel
My guess would be that -1.5 is 1.5 degrees before TDC.
And .05 would be .05 ATDC.
I am running about 10 BTDC, but mine is not exactly stock.
Yes, I have black smoke
Yes, I have power
Yes, it sucks down the fuel
#11
#12
Step 72 of assembly says"Put throttle shaft in idle position, squeeze throttle shaft and face cam tightly toward each other (using .005-in/.127mm feeler gauge) and rotate face cam so lower roller rests approximately in middle of low idle step, tighten screw to 30 lb-in". Hope this helps.
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